Many times I do not go out if the winds are high . I would be able to fit a Prindle 18 sail on my 19 ,but would this make enough of a difference with 2 feet shorter in luff and about 4 inch in foot ? I also have an old 19 sail that I can remove the bottom panel of 3 feet ..
Anyone have any experience on this ?
txs
Reefing by a smaller sail
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Posted: Jan 03, 2021 - 11:37 AM
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Posted: Jan 03, 2021 - 12:31 PM
Yes, I have a smaller mainsail I use in wind forecast to be over 20 mph.
But...
I also had my local sailmaker put reefing points on my primary mainsail and have used them several times in unexpectedly strong wind conditions. It is not very expensive to add reefing points and I have found it to be a nice "insurance policy". The more variable the conditions are where you sail the more I would consider adding reefing points.
Hope this helps,
Brad in Jacksonville, FL
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Posted: Jan 03, 2021 - 01:13 PM
great info .. on your primary mainsail , do you attach the downhaul and rear of boom to the reefing point holes ? -
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Posted: Jan 03, 2021 - 02:18 PM
you have grommets added and material (patches) added to reinforce the sail area
You can put smaller sails on a boat - good idea in heavier air but you may find some handling changes as a result as your CE has changed.
I have a 5.5 and a 6.0 (mystere)
i swap bigger and smaller jibs all the time depending on wind (on both cats)
i also use f18 sails in higher wind (they are significantly smaller than my 5.5 sail)
this makes a big difference
I also can put my 5.5 main on my 6.0 without any reefing needed to reduce power
I also have a reefing setup for my 6.0
sail is set up with reefing downhaul and leach grommets
there are "hoops" sewn into the sail so the bottom can be rolled up and secured with just a little line
I also have a oversized spinlock in my mast track to secure the halyard once it's reefed
I also use dyneema line with a jacket as my halyard to avoid any stretch once it's off the hook and running up and back down my mast
ONE BIG CAVEAT (ok 2)
1. when you take the sail off the hook and lower it - then secure the halyard on the base of the mast (or anywhere on the lower part) - you have changed your system from a 1:1 (hook : downhauil) to a 2:1 (halyard running up the mast, around a turning block : secured at the base on some cleat) - thus doubling the compression on your mast when you downhaul it. Add a couple human's on the wire, and a big gust - and you will be testing the tolerances of your hardware
best to make sure your mast can take this. my system has a 2:1 on the top of the mast that a marine engineer said would help distribute the loads above the spreaders. this is a semi common solution used for the added loads
2. sailing in heavy air with reduced sail area is a great way to handle the wind BUT your boat will still be a bear to hold on to while in the water/anchoring/parking, etc.. you still get all the spray in the face, water in the eyes and if you capsize you will have to deal with all this weather while righting - best to carry an anchor (ALWAYS unless racing WITH a chase boat) or you will be pushed without any steering until righted (and cat's sail away very well on their side) -
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Posted: Jan 03, 2021 - 07:30 PM
I don't think changing the way the halyard is rigged will have an effect on mast load. The downhaul is pulling with a given force. Shouldn't matter if it is pulling against the hook or a 10:1 setup, unless you also crank down on the halyard. -
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Posted: Jan 03, 2021 - 07:54 PM
i remember we discussed it a while ago. If you assume that friction is not significant, then the halyard tension would be the same as the downhaul tension, either one that you crank would have the same effect. So both equal forces pointing down would be the double compared to the downhaul forcé pulling against the hook. In practice there is friction, so the effect is something in between at the top of the mast. -
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Posted: Jan 03, 2021 - 10:01 PM
Bingo - by removing it from the hook you are also cranking down on the halyard (now unlocked)
thus the x amount of force your cunningham/downhaul are pulling is x times 2 (up the halyard and back down)
"Visualize a halyard lock at the top of the mast. With halyard locked it's 1:1 compression on mast to down force on halyard from Main.
Now with a 1:1 halyard, the halyard sheeve is a block and this creates a 2:1 purchase, so you actually have twice the compression force on the stick as halyard tension. "
http://forums.sailinganar…es-the-load-on-the-mast/
furthermore, adding a second block into the mix (say at the top of the mast like my 6.0 has) makes this 2x down to 1.5x
Ignoring friction losses... Mast compression is least with a halyard lock (1000N in this example), most with a 1:1 halyard (2000N) and 1500N with a 2:1 halyard. -
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Posted: Jan 04, 2021 - 12:58 AM
It's been a long time since my school days but I'm fairly certain that in a static load the sum of the external forces must be 0. So if the downhaul is pulling 60lbs the mast is resisting with equal force regardless of how the sail is rigged. Any mechanical advantage in the halyard should reduce the tension where the halyard is tied off.
I agree that more advantage on the halyard could increase the load on the mast a bit if the halyard stretches but it can't exceed the force applied by the downhaul. -
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Posted: Jan 04, 2021 - 04:39 AM
Forgot to mention a single block simply redirects the pull. Don't think it affects purchase. -
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Posted: Jan 04, 2021 - 06:26 AM
Right, no purchase if you compare the halyard side vs the downhaul side, the force is the same at both sides of the pulley. The double force is the resistance of the mast to hold the pulley, standing those two forces. Take the pulley as the system and those 3 are the external forces. -
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Posted: Jan 04, 2021 - 09:35 AM
Now what is arguable is whether you really need to apply the same downhaul force in both cases. On strong wind it's about bending the mast, not about stretching the sail or removing the wrinkles, which already happened under the forces applied. If the halyard is coming down through the mast track, then I think it's also helping to bend the mast in the same way as the downhaul, so probably you would need half the force on the downhaul (+ half the force on the halyard) for the same effect on the mast, compared to hooking the main at the top. -
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Posted: Jan 04, 2021 - 10:11 AM
From an earlier discussion
yes the forces on the sail / luff are the same, but on the mast (head) they are increased -
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Posted: Jan 04, 2021 - 10:18 AM
YES!
so 1/2 the downhaul = 100% downhaul with the sail on the hook
what happens when crew doesn't know this and applies 100% downhaul -
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Posted: Jan 04, 2021 - 12:08 PM
If there are marks they would be off, but it's another sail, the crew should not be expecting the same adjustments. And in my book its the captain's responsibility anyway...
But the risk could be mitigated by threading the downhaul with less purchase. -
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Posted: Jan 04, 2021 - 12:34 PM
agreed - many ways to handle the double compression on the mast
but at least we seem to agree now that there is more load on the mast by taking the ring off the hook -
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Posted: Jan 04, 2021 - 12:47 PM
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Posted: Jan 04, 2021 - 05:17 PM
Yes. I had a P-19 with a cut down Tornado main about 20 years ago. I cut 2' off the top to make a square top main. I made a short pennate on the head and just shackled the ring onto it. The head of the sail was about a foot down or so. But, it made a great sail for higher winds where I didn't want to use my race sails. Getting the ring to hook and unhook took a bit of a challenge, but it was doable. The sail ended up fitting on my 18-2 perfectly. There is no set rule.
The short answer is it will work if that's what takes to make it easy and get you on the water more. Some modification may look funny, but if it works... go with it.
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Scott
Prindle Fleet 2
TCDYC
Prindle 18-2 Mod "FrankenKitty"
Tornado Classic "Fast Furniture"
Prindle 19 "Mr. Wiggly"
Nacra 5.8 "De ja vu"
Nacra 5.0
Nacra 5.8
Tornadoes (Reg White)
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Posted: Jan 04, 2021 - 08:47 PM
what is that?
according to the dictionary it's a muscle?
i will assume you meant pigtail or something similar?
also how did you get the ring off the hook?
from what i have heard, extending the head ring via a pigtail will fight you all the way trying to get it off the hook since when you rotate the mast the ring will also rotate - and almost always require putting the boat on her side to get it off the hook -
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Posted: Jan 04, 2021 - 10:33 PM
I was about to ask the same thing and expose my lack of knowledge.
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Bryan in Poplar Grove, IL
Supercat 17, unknown year. Future project
Hobie 16, 1977 - died a spectacular death https://youtu.be/Y7O22bp2MVA
Hobie 16, 1978 - current boat
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Posted: Jan 05, 2021 - 11:08 AM
I have a Nacra 5.2 with reefing points on my mainsail and with covid I sailed much more solo than ever but on the windier days I still wanted to go out.I even did it on some race days at my club so I reefed the main and sailed in 10 to 15 knot winds and found it very manageable still a challenge to sail in those winds but I went out had a blast but under control I would highly recommend reefing points on your sails for those days you just have to get out there but your pushing the limits
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